Inspection method for instrument of high-low temperature damp heat test chamber
Maintenance method of high and low temperature hot and humid test chamber instrument The high and low temperature heat and humidity test chamber is also called a walk-in constant temperature and humidity test chamber. The simple distinction is that the constant temperature and humidity test chamber is more complex than the constant temperature and humidity chamber instrument, so it is necessary to overhaul it. To ensure the normal operation of the equipment. Industrial 3D Printers/Sand 3D Printers/Binder Jetting Additive Manufacturing Guangdong Fenghua Zhuoli Technology Co., Ltd , https://www.fhzlprinter.com
There are usually the following points for the following repair methods:
First, compare the specific method is: let the faulty meter and the normal meter operate under the same conditions, and then detect the signals of some points and then compare the measured two signals, if there is difference, you can conclude that the fault is out here. This method requires maintenance personnel with considerable knowledge and skills.
Two instruments of the same type are required and one is in normal operation. Use this method must also have the necessary equipment, such as: multimeter, oscilloscope and so on. Divided by nature, voltage comparison, waveform comparison, static impedance comparison, output comparison, current comparison, etc.
Second, the capacitor bypass method When a circuit produces a strange phenomenon, such as display confusion, you can use the capacitor bypass method to determine the circuit part of the fault.
Third, the isolation method fault isolation method does not require the same type of equipment or spare parts for comparison, and safe and reliable. According to the fault detection flow chart, segmentation and enveloping gradually narrow down the fault search range, together with signal comparison, component exchange and other methods, generally the fault will be found quickly.
4. The knocking method often encounters the phenomenon of good or bad operation of the instrument. The vast majority of this phenomenon is caused by poor contact or imaginary welding. For this situation, tapping and hand pressure can be used.
The so-called "knocking" is to lightly hit the board or component through a small rubber hoe or other knocker to see if it will cause an error or stop failure. The so-called "hand pressure" is when the fault occurs, after the power is turned off, the plugged parts and the plug and the base are again pressed firmly by hand, and if the power supply is turned on, it will eliminate the fault. If it is found that the case is normal, and if it is not normal to beat again, it is better to re-insert all the connectors and try again. If it is not successful, you have to find another solution.
Fifth, the state adjustment method In general, before the failure is determined, do not touch the components in the circuit, especially adjustable devices, such as potentiometers. However, if the paperless recorder first selects multiple reference measures (for example, position marks or voltage values ​​or resistance values ​​are measured before being touched), it is allowed to be touched if necessary. Maybe after some change, the fault will be eliminated.
The power and ground of the IC; the transistor circuit is connected across the base input or the collector output to observe the effect on the fault phenomenon. If the color paperless recorder bypasses its output when the bypass input of the capacitor is inactive and the fault disappears, a fault is identified in this stage of the circuit.
6. The observation method makes use of sight, smell and touch. In some cases, the damaged components will discolor, blistering, or burn spots; burned devices will produce some special odors; short-circuited chips will become hot; visible or unwelded areas can also be observed with the naked eye. .
Seventh, riding shoulder law riding shoulder method is also called parallel method. Place a good IC chip on the chip to be inspected, or connect good components (resistance capacitors, diodes, transistors, etc.) in parallel with the components to be inspected and maintain good contact if the fault is caused by an open circuit inside the device or For reasons such as poor contact, this method can be used to exclude.
Maintenance Method of High-Low Temperature and Humidity Test Room Instrument 8. Replacement Method
1) Element replacement method: Two identical instruments or sufficient spare parts are required. Replace a good spare with the same component on the faulty machine and see if the fault is eliminated.
2) Function replacement method: When the function of a part of the faulty machine is lost, because the original spare parts can not be found for a time, according to the circuit principle of the part, the procurement or self-made electrical parameters have the same function or near part replacement, and can also be achieved. The purpose of repairing the instrument.
Nine, lift the temperature method Sometimes, the instrument work for a long time, or in the summer when the working environment temperature is high, there will be failure, shutdown check is normal, stop for a period of time and then boot again and normal, after a while there is a failure. This phenomenon is due to the poor performance of individual ICs or components, and the high temperature characteristic parameters do not meet the requirements of the specifications. In order to find out the reason why the metal processing network, you can use the heating and cooling method.
The so-called cooling, that is, in the event of a failure, the use of cotton fiber will be wiped in place of possible failure of the alcohol to make it cool, observe whether the failure is eliminated. The so-called warming is artificially raising the temperature of the environment, such as using a soldering iron near the point of doubt (note that the temperature must not rise too high so as to damage the normal device) to see if the fault appears.
Maintenance method of high and low temperature hot and humid test chamber instrument 10. Exclusion method The so-called exclusion method is to determine the cause of the fault by inserting and inserting some plug-in board and device. When a certain plug-in board or device is removed and the meter returns to normal, it indicates that the failure occurred. This method is also a method that the technician should master and skillfully use. Hygrometer tester instrument maintenance method